PURPOSE: To cause a spiral antenna and dome to be compact and light by receiving a radio wave in a spiral coiling part, causing an optical wave to pass through an optical wave transmission surface and to condense by a condensing device, and detecting the optical wave with an optical wave sensor.

CONSTITUTION: Plural spiral coiling parts 1 are provided with intervals on an antenna surface 3 of a front surface and an antenna surface, excepting for the coiling part 1, is an optical wave transmission surface which is formed by an optical wave transmission material. Then, concave mirrors 4 and 4', which are provided with being faced each other in a cavity 6 in the back of the antenna surface 3, constitute the reflection type condensing device. The radio wave is received by the spiral coiling part 1 and an incident optical wave 7 is passed through the optical wave transmission surface 2, received to an optical wave sensor 5 by the convex mirror 4 and 4' and detected. Thus, since photo-detecting and reception devices for optical wave and radio wave are united, the antenna and dome can be made compact and light.